In this paper we propose an ontology (formal knowledge base) creation methodology based on integrating external ontologies into the one developed by a community of the do- main experts. We present the MarcOntX agent, a service, which allows to automate the process of generating suggestions of changes to the ontology. The suggestions are inferred from the external sources, such as large corpora of documents or concepts introduced by the users. We show the feasibility of our approach within two use case scenarios.